We are requesting funding to purchase a BD Biosciences Influx Cell Sorter to be integrated within the Hospital for Special Surgery (HSS) Flow Cytometry Core Facility. Cell sorting has been a critical technology provided to support NIH-funded research for investigators at HSS and at the Weill Cornell Medical College (WCMC), our affiliated academic partner, for more than twenty years. The Influx will replace the current BD FACS Vantage, purchased in 1994, which has been experiencing loss of functional capacity due to aging and no longer can be upgraded. The requested BD Influx cell sorter, as configured, will provide more rapid cell sorting speeds to allow for enhanced cell recovery and viability, and allow sorting by an increased number and variety of fluorochromes. More than forty laboratories use the sorting services provided by the HSS Core Facility. Research covers a broad range of studies in areas such as arthritis and tissue degeneration, autoimmunity and inflammation, soft tissue engineering and repair, cancer biology, and neurobiology. With the growth of the research scope of HSS and WCMC investigators and with the recent successful recruitment of new faculty members, it is imperative that those investigators have ready access to the instruments required for successful progress of their individual research programs. The new sorter will expand our capability, ensure that we can support the ongoing and currently funded NIH research and provide preliminary data for new NIH research studies.